Expansion of (1-x^2)/(1-2x-2x^2+x^3+x^4).

Terms

a(0) =1a(1) =2a(2) =5a(3) =13a(4) =33a(5) =85a(6) =218a(7) =560a(8) =1438a(9) =3693a(10) =9484a(11) =24356a(12) =62549a(13) =160633a(14) =412524a(15) =1059409a(16) =2720684a(17) =6987029a(18) =17943493a(19) =46080951a(20) =118341175a(21) =303913730a(22) =780485366a(23) =2004376066a(24) =5147467959a(25) =13219288954a(26) =33948652394a(27) =87184038671